Electric switch



March 15, 1960 H. P. LEWIS ET AL ELECTRIC SWITCH 3 Sheets-Sheet 1 Filed.Sept. 4, 1957 III 56 .Illl 52 INVENTORS HAROLD P. LEWIS Y JACOB SCHMIERATTORNEYS March 1, 1960 H. P. LEWIS ETAL 2,928,920

ELECTRIC SWITCH Filed Sept. 4, 1957 s She ets-Shee'c 2 l5 B I 2 r t 62 HLL] I FIG. 6

INVENTORS HAROLD P. LEWIS y JACOB seamen avrromwsvrs March 15, 1960 p, Lw s ET AL 2,928,920

ELECTRIC SWITCH Filed Sept. 4, 1957 3 Sheets-Sheet 3 l 58 "lu 54 g 4e s;0 46A 1o I 46 5e %/A 4+ I L I I2 A 42 5 L45 IN V EN TORS HAROLD WISFlG-e By JACOB s men Our invention relates to an electric switch whereina push button controls the electrical circuit by repeatedly pressing thepush button inwardly, whereby the-electrical contacts alternately closeand open.

The primary object of our invention is toconstruct a shallowelectricswitch wherein a ratchet wheel is securely mounted on the same shaftthat carries a cam that engages one of the electrical contacts.

Another object of our invention is to provide a switch I which is simplein construction and which has relatively few parts as contrasted withour switch as setforth in our prior filed application No. 570,302 newPatent No. 2,820,113, Jan; 14, 1958';

. Another object of our invention is to provide a simple switch whichhas a relatively small number of parts and which is easily andaccurately assembled."

7 Another object of 'our invention is to provide a switch which willcarry a heavy lead over a relatively long period of time without beingrendered inoperable.

In order to achieve the objects of our invention, we provide a pushbutton electric switch having. a pawl and ratchet wheel wherein thepawl, which is formed to serve as a pivot, and also to act as a pawlwher y the push button, when moved in one direction inwardly will rotatethe ratchet wheel one tooth together with itscomplementary cam; and thepush button when returned to its initial position will enable the springpressed pawl to pivot itself so that it will pass a consecutive ratchettooth and than be in a position to actuate the afforemer'n tionedconsecutive ratchet tooth.

Oher objects of our invention are to provide an proved device of thecharacter described} that isv easily and economically produced, which issturdy in construction, and which is highly etiicient in operation.

With the above and related objects in view, our invention consists inthe details of construction and combination of parts, as will be morefully understood from the following description, when read inconjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of an electrical push but ton switchembodying our invention.

Fig. 2 is an enlarged perspective view ofthe pawL;

Fig. 3 isa sectional view taken along the line 3-3 of Fig. 3.

itself.

Fig. 5 is a fragmentary sectional side view showing the Fig. 4 is afragmentary perspective view of the casing Fig. 7 is an enlargedfragmentary view showing the pivoted pawl and its ratchet wheel in itsnormal position. Fig. 8 is a view similar to Fig. 7 but wherein the pawlhas been pressed inwardly and has been released so that it passes theratchet wheel teeth freely.

Referring now in greater detail-to the drawings wherein similarreference characters refer to similar parts, we

aazsaa E V Patented Mar. 15, 1960 show an electrical switch having ahollow molded housing or casing, generally designated 'as A; a cover,generally designated as B, for thefhousing, and a push button, generallydesignated as C, which protrudes from the housing and the cover. I

The push button C is guided within the casing by-virtue of an opening inthe cover and by telescopinga rigidly mounted trunnion or guide 10,which is mounted within the bottom 12 of the casing A. The cover B is ofplastic insulation material and has mounted thereon a metal plate 15which is adapted to be attached to a switch box;

i The casing A has a chamber therein defined by a closed bottom'lz'andcontinuoussides' 14, 16, 18 and 20 which sides" generally form arectangle. The shorter sides 16 and 20 'each have'a protruding boss 22,which'has an opening 24 therein whereby a screw or bolt may passtherethrough to hold the cover. The sides 14 and 18 each have openings24 and 26 (Figs. 1 and 4) through which electrical connections may bemade to the ter-' minals of the switch and then reachto the bottom 12 ofthe casing cover. The bottom 12 and the sides 14, 16, 18 and 20 areintegrally molded to define the chamber which houses the. switchmechanism. Each of the sides 14 and 18 have through openings 24 and 26therein whereby wire attachingscrews 28 may be located whereby singlepole,

double pole or' 3-way switches may be used in the same Y.

casing. The interiorof the sides 14, 18 has a T-shaped slot 29thereinwhich serves to locateacontact which will behereinafter furtherdescribed. A narrow Wall 30 is integrally formed within the casing andit projects inwardly from one wall- 14 of the casing,and one end of thewall 30, is curved upwardly to serve as a bearing 32 which hereinafterWill be further described. A slot 34 in the casing serves to receive alocking strip 36 whereby the. ratchet shaft will be locked in position(see Fig. 3). An inwardly extending, vertical projecting T-shaped recess38 on the sides 14 and 1 8 of the casing'provides a housing lock for asecond terminal hereinafter to be further described. The bottom 12 ofthe casing has two projecting bosses 40 and 42 which prevent a flat,springlike pawl stop as from moving from side to side. lhe side 18 isconstructed in a similar fashion to the sideid so that a description ofone side suflices for a description of the other side, each sideinternally is a mirror image of the other side.

The control exterior portion 42 (Figs.- 7 and 8) of the bottom 12protrudes outwardly in order to provide a better base support for thetrunnion 10.

A freely mounted pawl, generally designated as D, is

telescoped by the trunnion 10 to'move inwardly with the movement of thepush button C, since a spring 46 surrounds the trunnion and the pawl ispressed by the spring 46 against the push button to engage and to move aratchet wheel, generally designated as E.

A shaft 45, mounted upon the bearings 32 in each wall 14 and 18 carriesthe ratchet wheel E and a contact actuating cam, generally designated asF. The rotation of the shaft 45 rotates the cam F and the ratchet wheel.

The helical spring 46 (Figs. 5 to 8) surrounds the trunthen 10 with oneend of the spring engaging the stop 44 on the bottom of the casing A andthe other end' engaging the pawl D which presse's'the pawl against thebottom of the push button C.

A detailed description of the pawl D (Figs. 2, 7 and 8)- impor'tant tounderstand its operation in the switch mechanism and is as follows. iThe pawl D has one end 48 inclined, at an angle of approximately 45 torest within an opening of the push button whereby the pawl D'cannotswing laterally out of position. The pawls canter 50 is horizontallyextending with respect to the bottom of the casing and it has an opening52 therethrough so that it is telescoped by the trunnion 10. The pawlhas an cit-set or pivot 54 (exaggerated in Figs. 7 and 8) therein, whoseupper surfaces pivotally engage the lower surfaces '8 of the push button0 in order to provide for an easy oscillation or pivotal mounting. Theother end56 of the pawl is inclined and shaped to readily engage one ofthe ratchet teeth E1, E2 or E3. It should be apparent at this stage thatwhen'the push button is pressed inwardly itcompels the spring pressedpawl D to move a ratchet tooth. The horizontally located ratchet toothstop 44 surrounds the trunnion 10 and is engaged by one tooth on theratchet wheel to prevent the rotation of the ratchet wheel in onedirection. When the push button is released, the pawl D of rigidmaterial, will be oscillated away from the tooth E2 (Fig. 8) on thewheel E by virtue of the pivotal engagement 54 of the pawl with thebottom 58 of the push buttonC and the tension of the helical spring 46which permits a slight oscillation of the pawl away from the ratchetteeth. In other words, the pawl being of rigid material, oscillates outof the way of the tooth which it has moved. The spring pressing againstthe pawl D enables the pawl always to move back into positionbecause thenormal tendency of the spring is to push the pawl whereby its centerportion is substantially parallel to the bottom of the push button. Theflat portion and the end or tail 48 of the pawl abutsthe push button tolimit its sway from side to side and its tilting against the ratchetteeth.

It is to be noted that one electrical contact, generally designated asG; fits within the T-shaped slot 29 and is stationary. The contact G isadapted to receive a terminal holding screw 28 through the opening 24 inthe casing A. 7

A flexible terminaLgenerally designated as H (Figs. 5 and 6) is adaptedto have one end engage the contact button on the stationary terminal Gwhereby the electrical circuit is closed. The flexible terminal H has abend therein 62 which rides upon the cam surfaces of the cam F. Theactuation of the cam F controls the opening and closing of the terminalsG and H whereby the electrical circuit is opened or closed, as describedin greater detail in our prior application, Serial No. 570,302.

Provision is made in the casing A whereby a second set of contacts G andH may be placedon the other side of the ratchet wheel E in order thatthe switch casing may be used as adouble pole or a 3-way switch.However, when the switch is made into a-double pole or a 3-way switch,another cam is added upon the shaft and additional contacts G and H areadded. The proper timing of the elements also is arranged. It is to benoted that the trunnion 10 serves a multiplicity of purposes. Itprovides a guide for the push button to keep the motion of the pushbutton in a rectilinear direction, it provides a guide for the spring46, and it firmly anchors the cam stop 44 against the bottom 12 of thecasing A.

In operation, two wires of a single line may be connected to thecontacts G and H of the switch by virtue of the screws 28, 28. In Fig. 5the contacts H and G are shown to be in open circuit position and toclose the circuit the button C is pressed inwardly whereby the bottom 58of the push button C abuts the pivot 5-4 of the pawl D. The pawl D movesalong the trunnion. The free edge of the pawl'end 56 engages a tooth onthe ratchet wheel E and movement of the pawl D inwardly towards thebottom 12 of the casing moves the ratchet wheel one tooth whereby thecam F is moved a distance to enable the U-shaped portion 62 (Figs. 5 and6) of one contact Hto drop thereby closing thecircuit through the G andH contacts. The push button in its outward movement permits the end ofthe pawl D to rock slightly around the pivot 54 and the end 69 of thestop strip 44 prevents any motion of the ratchet wheel E. The end 56 ofthe pawl D passes a toothon its upward movement of the push anchors thestop spring 44, and the projections 40, 42

prevent the stop spring from moving laterally. The ratchet E is alwaysin contact with the stop spring 44 whereby the end 60 is able to flex toabut the ratchet teeth to prevent their movement in one rotary directiononly.

Although our invention has been described in considerable detail, suchdescription is intended as being illustrative rather than limiting,since the invention may be variously embodied, and the scope of theinvention is to be determined as claimed.

We claim as our invention:

1. A switch, comprising a casing of molded insulation having. a chambertherein, a shaft, having a ratchet wheel and a cam securely mountedthereto, a trunnion securely mounted at substantially the center of thebottom of the casing, a separable molded casing having a central openingthereinand adapted to complete the enclosure for said casing,.a pushbutton, a helical spring surrounding said trunnion, a pawl mountedbetween said push button and said spring and guided by said trunnion,said push button having a recess therein, said pawl having a portionprotruding in said recess, an off-"set on said pawl engaging ihe innersurface of said push button whereby said pawl may rock, a pairofelectrical contacts, one of'said contactsbeing. securely mounted in saidcasing and a second complementary electrical contact being flexiblymounted in said casing, a ratchet wheel stop mounted on the bottom ofsaid casing and adapted to have one end abut the edges of the ratchetwheel teeth, said push button adapted to be moved inwardly within saidcasing against the outer force exerted by said helical spring wherebysaid pawl will move said ratchet wheel and upon the release of said pushbutton said pawl will move by the ratchet tooth it previously was inengagement with by rocking about said opening as a spring pressed pivotpoint.

.2. An electrical switch comprising a casing having-a pair of electricalcontacts, a rectilinear movable actuating button, a trunnion having aspring encircling said trunnion, a ratchet wheel, a cam, a shaft havingsaid rat'chet'and said cam secured thereto, a cam actuating pawl beingfreely pivoted against the bottom portion of said button and telescopedby said trunnion, one'end of saidspring pressing against an intermediateportion of said pawl, and one end of said pawl being adapted to actuatesaid ratchet wheel when said button is pressed inwardly and to move awayfrom said ratchet when the direction of movement ofsaid pawl isoutwardly.

3. An electrical switch actuated by a linear movement of a push button,either to open or to close the electrical circuit, comprising a moldedcasing having a bottom and sides defining a chamber, a trunnion securelymounted at one end within the bottom of said casing, a push buttonhaving an opening to interfit with one end of said trunnion, a coverhavinga push button opening therein and beingadaptcd to close saidcasing, a pawl loosely mounted upon said trunnion, a spring encirclingsaid trunnion, a pivotal projection on said pawl and being adapted topress said pawl against the bottom of said push button,-a ratchet wheeladapted to be actuated by said pawl, a shaft on which said ratchet wheelis mount- 'ed, a cam mounted upon-said shaft, and an electricalcontactjadapted to be actuated by said cam, a spring held imposition bysaid trunnion and being adapted to prevent the rotation of-said ratchetwheel in one direction. I

4. An electrical switch comprising a casing having a. pair of electricalcontacts, a rectilinear'movable actuata. r, sesame 5 6 ing button, aratchet wheel, a cam, a shaft having said ton is pressed inwardly and tomove away from said ratchet wheel and said cam secured thereto, a camacturatchet wheel when the direction Of movement Of said ating pawlfreely and flexibly pivoted against said button, p 15 outwardlya springi1.1.said casing guide meians for Said i Said References Cited in thefile of this patent spring resiliently urging both said button and saidpawl 5 outwardly of said casing, and one end of said pawl be- UNITEDSTATES PATENTS ing adapted to actuate said ratchet wheel when said but-2,721,914 Cheltz Oct. 25, 1955

